// 实现这个项目的构建任务

const { src, dest, parallel, series, watch } = require('gulp')
const del = require('del')
const browserSync = require('browser-sync')
const loadPlugins = require('gulp-load-plugins')

const bs = browserSync.create()
const plugins = loadPlugins()
const sass = plugins.sass(require('node-sass'))

const data = {
  pkg: require('./package.json')
}

const clean = () => {
  return del(['dist', 'temp'])
}

const style = () => {
  return src('src/assets/styles/*.scss', { base: 'src' })
    .pipe(sass({ outputStyle: 'expanded' }))
    .pipe(dest('temp'))
}

const script = () => {
  return src('src/assets/scripts/*.js', { base: 'src' })
    .pipe(plugins.babel({ presets: ['@babel/preset-env'] }))
    .pipe(dest('temp'))
}

const page = () => {
  return src('src/*html', { base: 'src' })
    .pipe(plugins.swig({ data, defaults: { cache: false } }))
    .pipe(dest('temp'))
}

const image = () => {
  return src('src/assets/images/**', { base: 'src' })
    .pipe(plugins.imagemin())
    .pipe(dest('dist'))
}

const font = () => {
  return src('src/assets/fonts/**', { base: 'src' })
    .pipe(plugins.imagemin())
    .pipe(dest('dist'))
}

const extra = () => {
  return src('public/**', { base: 'public' }).pipe(dest('dist'))
}

const serve = () => {
  watch('src/assets/styles/*.scss', style)
  watch('src/assets/scripts/*.js', script)
  watch('src/*html', page)
  watch(['src/assets/images/**', 'src/assets/fonts/**', 'public/**'], bs.reload)

  bs.init({
    notify: false,
    port: 2080,
    files: 'temp/**',
    server: {
      baseDir: ['temp', 'src', 'public'],
      routes: {
        '/node_modules': 'node_modules'
      }
    }
  })
}

const useref = () => {
  return src('temp/*.html', { base: 'temp' })
    .pipe(plugins.useref({ searchPath: ['temp', '.'] }))
    .pipe(plugins.if(/\.js$/, plugins.uglify()))
    .pipe(plugins.if(/\.css$/, plugins.cleanCss()))
    .pipe(
      plugins.if(
        /\.html$/,
        plugins.htmlmin({
          collapseWhitespace: true,
          minifyCSS: true,
          minifyJS: true
        })
      )
    )
    .pipe(dest('dist'))
}

const compile = parallel(style, script, page)
const build = series(
  clean,
  parallel(series(compile, useref), image, font, extra)
)
const start = series(clean, compile, serve)

module.exports = {
  clean,
  serve,
  build,
  start
}
